A laser diode is an electro-optical device in which an intrinsically-doped, direct-bandgap semiconductor zone separates opposing p- and n-doped zones. Under forward bias, the p- and n-doped zones inject charge carriers into the intrinsically-doped zone, which is configured as a laser cavity. When electrical current is injected into the diode laser, an inverted population of electrons and holes accumulate within the quantum well of the laser diode. Some of the accumulated charge carriers may recombine by stimulated photon emission, causing a coherent beam to emerge from the laser cavity. A laser diode may be used in electronic-display applications.
In some laser display applications, it is desirable to have low power usage in order to enable long life battery operation. The threshold current requirement of the laser diode typically dictates the majority of the energy loss in the lasers and adjusting the bias of the laser diode can reduce power usage. Reducing the bias voltage will reduce the power usage. However, a lower bias voltage increases the likelihood of saturating the laser diode while outputting a display signal.
Also, the voltage-current characteristics for laser diodes can vary greatly with temperature. The biasing voltage for the laser diode may be adjusted to compensate for the effects of temperature based on an estimate of the junction temperature of the diode. However, conventional approaches to temperature compensation are often inaccurate, slow, or both. The disclosure made herein is presented with respect to these and other considerations.